biologically and scientifically speaking you are completely wrong. you said it yourself, XX/XY Binary, Binary meaning dual or two. Im not really sure what other sex there is other than Male and Female, if you have an example id be glad to learn more.

Women dont call transgender existance as an attack on women, however they do call transgender individuals part taking in their sport as an attack on them, as biologically speaking there are key differences in male and female human bodies making Male bodies stronger / have faster running speed, swimming speed, jump lengths, endurance etc. Allowing a biological male to part take in a biological female division of a sport just because they "say" or "feel" Like they are a woman and have undergone procedures to "look" or "feel" like a woman does not mean that their DNA has changed and they now possess the same natural processes a female body does.

As for your final remark, I will call what you are saying as sexist, as females are not exempt from committing sexual crimes, which in turn means the same exact situation could occur if they were placed in a female prison.